In The Great Gatsby what happens before and after the parties that Gatsby throws?

Gatsby throws killer parties that everyone wants to attend. After his house is just wrecked and he has to clean up the pieces. He doesn't even know most of the people who attend.

The beginning of the third chapter states that five crates of Oranges and lemons arrived every Friday from a fruiterer in New York to be juiced for his parties and that the pulpless halves left every Monday from his back door. It also says that caterers often came and produced buffet tables of food and that a full orchestra came in.